As a result of my research, it became clear that there were differences in amounts of Mn and REE of allanite subgroup minerals between granitic rocks and pegmatite in Innor Zone of southwest Japan. Behavior of Mn and REE may be different between Hiroshima granitic pegmatite and Ryoke granitic pegmatite. Allanite subgroup minerals of the pegmatite in Innor Zone of southwest Japan are characterized to be rich in Mn, Y, MREE and HREE. On the other hand, allanite subgroup minerals of granitic rocks are rich in LREE, and poor in Mn and Y. Moreover, uedaite-(Ce) was found out at 4 localities of Tateiwa Mine, Sho Mine, Ishitegawa dam and Omishima Island. In addition, the mineral corresponding to phase of uedaite-(Y) was also discovered.

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Monoclinic epidote-group minerals have two A sites (A1 and A2) as a coordination site. A site is commonly occupied by Ca; ninefold-coordinated A1 and tenfold-coordinated A2 sites. The A2 site is slightly larger than A1 site, and its size increases with incorporation of Fe³⁺ and Mn³⁺ in M1 and M3 sites. The A2 site is large for Ca (1.23A) (Dollase, 1971), however this site readily incorporates Sr (1.36A) and larger cations. For these crystallochemical features, Sr epidote is not rare (Nagasaki & Enami, 1998 ; Miyajima et al. 2003; etc). In Kurosegawa Zone of Itsuki Village, Kumamoro prefecture, a tectonic block in serpentnite and Haki metamorphic rocks (Oshima, 1979) are distributed. The former is composed mainly of lawsonite blueschist, and the latter consists mainly of greenstone . This study reports on Sr-rich epidotes in the tectonic block of serpentinite and the Haki metamorphic rocks.

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Oxidation state and distribution of Fe in pumpellyite was studied using Mössbauer and X-ray Rietveld methods. The sample was collected from greenstones, Chichibu belt, Ehime Prefecture. The pumpellyite contained 10.01wt.% total Fe₂O₃ on average. By applying the Fe²⁺:Fe³⁺-ratio determined by the Mössbauer analysis, and the Rietveld method together with chemical analysis, the resulting formula of Chichibu pumpellyite is (Ca_7.95Na_0.01K_0.02)_Σ7.98(Al_1.58Mg_1.21Fe³⁺_0.61Fe²⁺_0.53Mn_0.09)_Σ4.02(Al_6.51Fe³⁺_1.49V_0.02Ti_0.01)_Σ8.03Si_12.25O_40.75(OH)_15.25. The intracrystalline distribution coefficient of Fe³⁺ and Al between the X and Y sites [K_D = (Fe³⁺/Al)X/(Fe³⁺/Al)Y] is 1.69, indicating a stronger preference of Fe³⁺ in the X site.

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Coexistent txture of celsian and cymrite at equilibrium is found in some veinlets running across jadeitites or their associated rocks from the Wakasa district, Tottori Prefecture. The veinlets are mainly composed of the prismatic jadeite crystals. Pale-yellow coloured spots are occasionally observed in the veinlets, which are composed of the intergrown aggregates of itoigawaite-pumpellyite. Celsian and cymrite are distributed along the boundary of the pale-yellow spots. We can constrain the formation conditions of the jadeite veinlets on the basis of the coexistence of celsian and cymrite and the presence of pumpellyite.

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The first occurrence of axinite-(Mg) in Japan has been recognized at Kashio-river bed as a small boulder. Zoning of the chemical composition corresponding to axinite-(Mg) and axinite-(Fe) is observed. The mole of axinite-(Mg) varies 58% to 23%. Boron content also varies 1. to 0.63 apfu, and the insufficient boron is filled with the increase in silicon.Excess silicon maybe replace boron in the BO4-tetrahedron.

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Typical cyclosilicates, cordierite and beryl, form a channel which is a pipe-like cavity. It is known that two types of water molecules called type I and type II are trapped in the channel. Type I orients its H-H vector parallel to c-axis (channel direction). When a cation such as Li+ or Na+ locates near the water molecule, it reorients to become type II, so that its H-H vector is perpendicular to c-axis. High temperature and quenched room temperature infrared spectra were measured for natural cordierite and beryl. The stability and dehydration behavior of the both types of water molecule will be discussed by observing the peak shift and peak broadening. The changes of peak frequency of type II water can be explained by the change in coordination number to a cation.

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A clathrate mineral has been found from sandstone and mudstone of the Miocene Hota Group in Arakawa, Chiba Prefecture, Japan. Fine fissures are developed in the sediments, some of which are filled with quartz and calcite vein. The clathrate mineral occurs in quartz vein and druse in the quartz vein. While most of the crystals are quartz pseudomorph after the clathrate mineral, we found some fresh crystals. Rietveld and MEM analysis of X-ray powder diffraction data have been performed since all the crystals have pseudo-merohedral twinning. The crystal system is tetragonal and the lattice parameters are a=13.7190(9), c=19.349(1). The framework of the clathrate has the MTN type structure. Raman peaks of methane molecules in guest sites in the cages are observed.

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Hyalite in pegmatite from Naegi Granite may fluoresce under ultraviolet rays. To clarify the cause of fluorescence and fluorescence property of hyalite, three different hyalite of locality were examined by WDX, FT-IR, and fluorescence spectroscopy. Chemical analysis and fluorescence spectroscopy shows that fluorescence is correlated with U. In addition, the fluorescence weakens by heating.

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Trace element contents of single fluid inclusions in quartz from miarolitic cavities, pegmatites, and quartz veins at the Kofu granite body, Yamanashi Pref., Japan, were analyzed by particle-induced X-ray emission (PIXE) to elucidate the compositional change of hydrothermal fluids during a migration in granite body. Most of fluid inclusions in the Kofu granite were two-phase inclusions (5-10 wt.% NaCl eq.), while polyphase inclusions (30-38% NaCl eq.) were also observed in hydrothermal quartz veins near the elevations of 1200 m. Determined contents are as follows: ∼8 wt.% for Cl, 2-6 wt.% for K and Ca, 1000-3000 ppm for Fe and Ba, 200-500 ppm for Mn, Zn, Pb, Cu, Br, and Ge, several tens ppm for Rb and Sr in the two-phase inclusions; ∼17 wt.% for Cl, 2-3 wt.% for K and Ca, 2000-10000 ppm for Fe, Mn, and Zn, 200-700 ppm for Pb, Cu, Br, Sr, Ba, and Rb, 20-30 ppm for Ge in the polyphase inclusions.

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Oxidation state and distribution of Fe in olivine oxidized at high temperatures were investigated. The samples of andesitic scoria and lava were collected from Kasayama volcano, Hagi, Yamaguchi Prefecture. The Fo contents of olivine in reddish black and black scoria are 83-85 and 79-81, respectively. The Fe²⁺:Fe³⁺ ratios in olivine of those scoria were 92-93:8-7 and 93-98:7-1, respectively. The Fo contents of olivine in reddish black and black lava were 79-80 and 73-80, respectively, and the Fe²⁺:Fe³⁺ ratios ranged from 92-99:8-1 and 93-99:7-1, respectively. On the basis of atomic contents at M1 and M2 and the Fe²⁺:Fe³⁺-ratio in olivine from the reddish black scoria, the chemical formula of the olivine was derived as [(Mg_0.835Fe²⁺_0.165)^M1 (Mg²⁺_0.830 Fe²⁺_0.053Fe³⁺_0.117)^M2]_Σ2.000Si_1.000O₄.

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The relationship between Raman spectra and crystallographic orientation was examined for single crystals of Fo₈₉Fa₁₁ olivine [(Mg_0.89Fe_0.11)₂SiO₄]. Raman spectra were obtained for chemically homogeneous olivine grains with various orientations on a thin section of dunite using micro-Raman equipment and an unpolarized exciting laser. Crystallographic orientations of each olivine grain were determined using an electron backscattered diffraction (EBSD) method. Five apparent peaks at 822 (p1), 854 (p2), 880 (p3), 917 (p4), and 959 cm^-1 (p5) were observed in the spectral range of 700- 1050 cm^-1. Intensity ratios of p-i to p2 , Ii/I2, for i = 1, 4, and 5 were formulated empirically as functions of crystallographic orientations. These empirical equations well describe the relationships between Ii/I2 and crystallographic orientation and enable Raman spectroscopic determination of the crystallographic orientation of olivine.

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Unknown mineral, which consists mainly Fe, Mg, As, Si, O and H, was found in druse or surface of Loellingite in a skarn mine at the Kiurakozan, Oita Prefecture, Japan. It occurred as a column or fibrous crystal up to 1 mm long in association with scorodite and Arseniosiderite. The composition image of one grain shows two kinds of parts which different in brightness. An electron microprobe analyses of bright and dark parts showed the presence of Fe, Mg, As and Si, and Mg and Si, respectively. The infrared absorption spectrum of mixed powder of bright and dark parts showed OH stretching vibration though no vibrations associated with the carbonate group. The X-ray micro-beam diffraction (PSPC-MDG) data for each part was similar to each other.

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Zálesíite is found out from Cu-rich hydrothermal vein intruded into the crystalline limestone of the Fuka Mine, Okayama Prefecture, Japan. This zálesíite is characterized by free REE and bearing Bi. Coexistent minerals of zalesiite, andradite, aragonite, cahnite, conichalcite, cuprite, johnbaumite and stringhamite are observed. Bearing Bi is observed within conichalcite. Moreover, it is characteristic that bornite, chalcocite, chalcopyrite and wittichenite are observed in calcite as primary minerals. Of which, wittichenite is rarely included in calcite with grain size less than 5μm. It is thought that this hydrothermal vein was formed in the plural stages. It is supposed that Cu-rich fluid intruded first, and the fluid abundant with Bi and As passed along the vein later.

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Hydrowoodwardite was found from the Dogamaru mine, Shimane Prefecture, Japan.

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Potassic-ferropargasite, ideally KCa₂(Fe²⁺₄Al)Si₆Al₂O₂₂(OH)₂, occurs in a calcareous metamorphic rock from Kabutoichiba, Kameyama, Mie Prefecture, central Japan. It is monoclinic, space group C2/m, with refined unit-cell parameters a = 9.937(5), b = 18.108(5), c = 5.335(4) Å, β = 105.30(3)°, V = 926.0(9) ų, Z = 2. The mineral and mineral name were approved by the IMA, CNMNC, #2007-053.

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Momoi and Yoshimura(1964) found a goldmanite(Ca₃V₂Si₃O₁₂)-Mn-V-garnet series garnet from Yamato mine in Kagoshima Pref. Japan. They proposed a new mineral Yamatoite(Mn₃V₂Si₃O₁₂ ). However, this garnet was not approved by IMA, because the site occupancy of Mn is less than Ca. A garnet from the Kurase mine is greenish-yellow in color. And grain diameter is smaller than 0.1mm. Greenish-yellow garnets have 3 types, euhedral crystal, vein and indeterminate form. Associated minerals are Mn-calcite-tephroite, Ca-rhodochrosite and Ca-rhodochrosite-tephroite-vuorelainenite, respectively. Occurence of associated minerals are indicative of order of crystallization. First, greenish garnet was crystallized out. Next it was dissolve. Finally Ca-Al rich garnet was resorption overgrowth. I will reported the result of synthetic experiment of Mn-V bearing garent in this study.

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Tucekite, a member of hauchecornite group of minerals, is found from the Takanosu mine, metamorphosed manganese ore deposit, which is known for the occurrence of manganpyrosmalite. Tucekite occurs as euhedral crystals of tetragonal prism up to 4mm length and 1mm width in a cavities or fissures of mangan- pyrosmalite group of minerals and rhodonite. Chemical analysis by EPMA shows the ratio of Ni:Sb:S=9:2:8. Principal lines of reflection obtained by a X-ray powder diffraction method (d/I) are, 4.33(52), 3.61(46), 3.24(82), 3.00(9), 2.77(100), 2.52(40), 2.38(65), 2.29(44), 2.07(40), 1.852(42), 1.802(42), 1.794(58), 1.741(11), 1.662(10), 1.567 (18), 1.498(4), 1.469(2) and lead to lattice parameters; a=0.7216 , c=0.5383(nm).

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I report on orcelite which found from Higashi-akaisi peridotite mass, Nikubuti mass and peridotite from Dozan River. Higashi-akaishi peridotite mass which size is about 5km East-West 1.5km North-South extension locates on central Sikoku Sambagawa Zone. Orcelite which given Ni_5-xAs₂ is a rare mineral of the production worldwide. Orcelite is associated with pentlandite, heazlewoodite, awaruite and native copper. Orcelite composed Metal:66.87-63.58wt%, As+Sb+Bi:32.51-34.95wt%. If As+Sb+Bi=2, orcelite's empirical formula is M_4.699As₂-M_5.277As₂(M=Ni and small amounts Fe, Co, Cu, Ag). Then, I report on irarsite and native nickel.

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Horomanite and samaniite are found in the interstitial grains of olivine aggregate in lherzolite of the Horoman peridotite massif, Samani town, Hokkaido, Japan. The analytical data by EPMA for horomanite are Cu: 0.43, Fe: 41.82, Ni: 23.76, Co: 0.52 and S: 33.29, with a total of 99.52wt%. The empirical formula is (Fe5.77Ni3.12Co0.07Cu0.05)9.00S8.00. Crystal data by X-ray single crystal (precession) and powder diffractions for horomanite are tetragonal symmetry, a=10.566 , c=9.749 , and Z=4. The chemical compositions obtained by EPMA of samaniite are Cu:16.90, Fe:34.60, Ni:15.48, Co:0.16, and S:32.87 with total of 100.10wt%. The empirical formula is Cu2.08(Fe4.84Ni2.06Co0.02)6.92S8.00. The crystal data by X-ray single crystal and powder diffractions for samaniite are tetragonal symmetry, a=10.089, c=10.402, and Z=4.

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An anomalous internal textures was found out for zircon in Ashizuri-misaki Ring Complex, Kochi, SW Japan. The five types of anomalous texture distinguished in the zircon, and the disturbance progressed from core toward rim ("inner disturbance") and/or the one progressed from rim to core ("outer disturbance") were commonly in the zircon population among these textures. Despite showing these textural features, the morphology of these zicon clearly indicates that they are igneous. We discussed progression sequence of these textures by the contact relations, and we'll clarifying the genesis of each texture using chemical or isotopic technique.

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Obsidian, part of the rhyolite lava flow in Omekura area eastan of Wada Toge, contain spherulites consisting mainly cristobalite and albite, and rarely pyroxene, oxide and airspace. We suggest that lithophysae and spherulites crystallization stage in Wada Obsidian. Spherulites and lithophysae grew near anguli of phenocrysts, and therefore cavitation by the phenocryst triggered those crystal growth.

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Crystal structures of vanadian garnet from the Sor Rondane Mountains, East Antarctica, were analyzed to examine the structural variations caused by the substitution of V for Al. The atomic contents at the octahedral sites derived from EPMA analyses are as follows; Type 1 garnet (large porphyroblast): Fe0.01V0.08Cr0.02Ti0.03Al1.86, Type 2 garnet (garnet in kelyphite rim): Fe0.21V0.69Cr0.18Ti0.03Al0.99, Type 3 garnet (fine-grained porphyroblast): Fe0.20V0.96Cr0.23Ti0.03Al0.68. Unit cell parameters are 11.859 (type 1), 11.926 (type 2) and 12.0152 Å (type 3). The mean Y-O distances increases with increasing V in the octahedral site: 1.932 (type 1), 1.97 (type 2) and 1.987 A (type 3).

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Crystal structure of chromian pumpellyite was analyzed using single-crystal X-ray diffraction method in order to investigate behavior of chromium between two independent octahedral sites. The chromian pumpellyite was collected from basic schists in the Osayama ultramafic body, Okayama Prefecture. The Cr distribution is heterogeneous, and maximum Cr₂O₃ content is 13.3 wt%. The refined occupancies of Al_X, Cr_X, Al_Y and Cr_Y are 1.50, 0.21, 7.67 and 0.24, respectively. The distribution coefficient of Cr and Al between the X and Y sites [(Cr/Al)_X/(Cr/Al)_Y] is 3.48 and 1.92, indicating a stronger preference of Cr for the X site. The unit cell parameters are greater than those of Mg-Al-pumpellyite, because of the Al↔Cr substitution. It is consistent with mean Y-O distances.

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The crystal structure of sursassite, Mn²⁺₂Al₃Si₃O₁₁(OH) ₃, from four different localities were investigated to find the structural and compositional relationships between sursassite and iso-structural macfallite including the nature of their hydrogen-bonding systems. There are three octahedral sites, M1, M2, and M3. Divalent cations order preferentially on M1 whereas in all samples M2 is occupied by Al only. Although there are three main hydroxyl groups occurring in sursassite, the exact number depends on the concentration of trivalent and divalent cations at the M1 site. If divalent cations occur at M1, a fourth OH group is necessary to maintain charge balance. Due to the influence of divalent cations on M1 in sursassite, the hydrogen-bond systems in sursassite and iso-structural macfallite are different.

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Macfallite from Keweenaw, Michigan, USA, was studied using electron microprobe, thermogravimetry, differential thermal analysis, powder Fourier transform infrared spectroscopy and single-crystal X-ray diffraction methods. The formula is (Ca_2.03Na_0.01)_Σ2.04(Mn³⁺_2.51Al_0.27Mg_0.09Cu²⁺_0.03V³⁺_0.01)_Σ2.91Si_3.05O_10.88(OH)_3.12 (Z = 2), and The cell parameters are: a = 8.959(3), b = 6.072(2), c = 10.218(4) Å, β = 110.75(3)° (P2₁/m). The site populations at the octahedral M1, M2 and M3 sites are Mn_0.82Al_0.06Mg_0.09Cu_0.03, Mn_0.75Al_0.25 and Mn_0.95Al_0.05, respectively. Three OH groups are located at the O6, O10 and O11. The O7 is occupied not only by oxygen but also by minor amounts of OH. The FTIR spectrum shows three strong OH bands at 3413, 3376, 3239 cm^-1 and an additional broad absorption OH band around 2900 cm^-1.

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High-temperature synchrotron X-ray powder diffraction experiments for the composition of (Ca0.06Mg1.94)Si2O6 have been carried out in the present study to clarify whether orthopyroxene has a transition between low- and high-temperature phases. Our results show that discontinuous changes of unit-cell dimensions and volume occur at 1170°C during both heating and cooling processes and that the space group of Pbca does not change during this reversible phase transition. These facts indicate a first-order and isosymmetric phase transition. This high-temperature phase is thermodynamically distinct from the low-temperature phase, i.e., orthoenstatite in the Mg-rich portion of Mg2Si2O6-CaMgSi2O6 phase diagram, although they have the same space group.

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Materials with a perovskite structure in the CaTiO₃-NdAlO₃ system were examined to reveal Mg²⁺Si⁴⁺O₃- Fe³⁺Al³⁺O₃ perovskite in the Earth's lower mantle. Samples were synthesized from constituent simple oxides at 1723K in air using a muffle furnace. Synthesized samples were characterized by X-ray diffraction, SEM-EDS and TEM. SEM-EDS observation showed that the run products were chemically homogeneous. XRD experiments suggested that the phase has the perovskite structure in the orthorhombic system (space group Pbnm). TEM observations suggested that this perovskite has 10 nm to 100 nm size twin domains. Those twins are possibly induced by some structural transformations during the cooling process.

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A new high-pressure phase with the composition of Mg2Al2O5 was found. A crystal structure model of the Mg2Al2O5 phase was constructed based on that of ludwigite because the X-ray diffraction pattern of the former is very similar to that of the latter. In the model, (Mg, Al)O6 octahedra connected by edge-sharing and corner-sharing form triangular tunnels in which Mg ions are accommodated. Mg ions in the tunnels have a coordinate environment with trigonal prism-type MgO6. Systematic absences of reflections indicate that the space group of the structure is Pba2 or Pbam. The Rietveld analysis showed that R factor in the case of Pbam was smaller than that in the case of Pba2. This result suggests that the space group of the Ma2Al2O5 phase is Pbam.

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Using Cs-corrected STEM=HAADF, Th single atoms were observed, for the first time, in metamict mineral of thorite which occurred from Ashizuri complex.

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Structure of bamboo leaf silica and its evolution by heat treatment were invesitated by using X-ray diffraction and IR techniques. Silica components extracted from bamboo leaf has the structure between silica-gel and silica glass which includes silanol group (Si-OH). By heat treatment up to 1150°C, absorbed water of silica component was dehydrated at 600°C, and the OH group in the SiO4 frame work strcture was also dehydrated at 1000°C, and additional Si-O-Si bonds were formed. 4-membered rings of SiO4 tetrahedra of non treated silica also transform to 6 membered siloxane ring by heat treatment.

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Crystal structure of nesquehonite thermal decomposition product was solved by Monte Carlo method and refined by Rietveld calculation. Nesquehonite(MgCO3·3H2O), synthesized from Mg(OH)2 aqueous solution and CO2 gas, was heated by 30°C/min up to 600 °C. Then the intermediate phase was observed between 300 and 500 °C. DTA-TG data and EPMA analysis shows that the formula of the phase is 3MgO·2CO2. The powder X-ray diffraction data of intermediate phase indicate that the possible space group is I-43m, I43m or Im3m. The structure model-assembly program (Miura and Kikuchi, 1999) found the suitable structure model and Rietveld refinement confirmed the structure.

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A qualitative understanding of the incorporation of hydrogen atoms in forsterite and corresponding octahedral vacancies are given from the inspection of the crystal structure with the view point of minimum strain configuration. In the case of Fe-free hydrous forsterite, the structural strain from the ideal size is larger in M1 site than in M2 site. Two H atoms may replace the Mg atom predominantly at the M1 site to reduce the structural strain, giving the vacancy at the M1 site. In the case of Fe-bearing hydrous forsterite, two H atoms may replace the Mg atom predominantly at the M2 site to avoid the combination of Fe-Mg for M1-M2 sites for the reduction of the structural strain, giving the vacancy at the M2 site. In both cases, the most probable H atom locations are near to the edges of MO₆ octahedra.

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Allanite is a member of the epidote group minerals with the general formula (Ca,RE)(Fe²⁺,Fe³⁺,Al)₃(Si₂O₇)(SiO₄)O(OH). Allanite incorporates radioactive elements like U and Th and indicates metamicitization. We demonstrate the structure of the metamicted allanite from Teofilo, Otoni, Brazil by using the results of radial distribution function and transmission electron microscopy techniques.

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Tourmaline is unique among gem minerals in occurring in shades of all colors. In this study, local structure around Mn in rubellite from Mogok Myanmar and cuprian elbaite from Dos Quintos Brazil is analyzed by XAFS (X-ray Absorption Fine Structure) measurements. The energy of the K-absorption edge for present elbaite samples is similar to that of MnO, by suggesting the overall preference of Mn²⁺. The first nearest neighbor distance of Mn-O pair is about 0.22nm, which also suggests the local structure around Mn²⁺.

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Three kinds of superstructures of wollastonite were synthesized. The two among three are twice as large as the basic structure. However, they have different structures. One has the stacking of the two basic-wollastonite units with b/2 displacement. The other has the two non-displacement units of the basic wollastonite. The third superstructure is four times as large as the basic structure. It has the four non-displacement units of the basic wollastonite.

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The ordered structure of An25 to An75 plagioclase, called "e-structure" is extremely peculiar. The e-structure had been reported in only metamorphic rock and plutonic rock that kept at relatively cooler temperature. The e-structure was observed for the first time in volcanic rock which is icelanditic dacite that occurred in Motegi region.

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Structures of NaAlGe3O8-KAlGe3O8 feldspar glasses were investigated by using X-ray diffraction measurement, infrared spectroscopy. Structure parameters such as T-O and T-T distances (T=Al/Si) were obtained by radial distribution function analysis based on observed X-ray diffraction intensities. Observed densities of glasses were decreased with increasing K2O content. This density change is correlated with both short and medium range structure of glasses.

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Structural change of K-feldspar by mechanical grind were investigated by X-ray diffraction measurement and IR spectroscopy.X-ray diffraction intensity of 020,002 reflections decrease rapidly by about10hours grind.With more grinding,intensities of all refrections decrease continuously and became to amorphous like by 1200 hours grind.In IR spectra also became broad with increasing grinding time.
These result may indicate K-feldspar became to be amorphous like structure by 1200 houres grind and are similar to result on the structural change by shock compression.On the other hand,Si-OH band at about 900cm-1 IR spectra were found with more than 300 hours of grind.Si-OH band has not been observed shock compressed K-feldspar.Therefore,this fact suggests that Si-O-Si and Si-O-Al linkage in K-feldspar crystals are partially broken and Si-OH pairs are newly formed during grinding by ball mill.

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In this study, shark teeth enamel was investigated by mineralogycal technique. Hydroxylapatite was included in shark teeth enamel. Shark teeth enamel was observed by polarized microscopy.Shark teeth enamel was analyzed by XRPD method. Shark teeth enamel was examined in detail by polarized FT-IR microscopy. X-ray diffraction pattern was analyzed by using Weisenberg and precession camera. From the result, it was comfirmed that c-axies of hydroxylapatite was preferred oriented to direction of longitudinal enamel prism and direction where it is done to angle of about 30 degrees.

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Ferrihydrite transforms into goethite or hematite crystals. The transformation rate is proportional to the amount of ferrihydrite. This study discusses the transformation mechanism to explain the transformation rate. The formation rate of crystal is proportional to the surface area of crystals because the dissolution of ferrihydrite is very fast. The surface area of crystals is proportional to the nucleation rate of crystal if the crystals stop growing at a certain size. The nucleation rate is proportional to the surface area (or the amount) of ferrihydrite if the crystals nucleate only on the surface of ferrihydrite. As a result, we can prove that the formation rate of crystals is proportional to the amount of ferrihydrite assuming that the crystals nucleate only on ferrihydrite and stop growing at a certain size. Thus, the rate-determining process of the transformation of ferrihydrite to crystals is the nucleation of the crystals on ferrihydrite.

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Grain growth of forsterite is examined in this study.

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Synthesis of anorthite crystal was tried by using the flux of CaO-V₂O₅-Li₂O-B₂O₃. In the present study, it has been shown that the addition of Li₂O or B₂O₃ increased the mobility, which contributed to lower the growth temperature. Under some conditions, for example in the case of cooling from 1200 to 1050°C, transparent anorthite crystals in platy habit up to a few millimeters in size have been obtained successfully. It has been also found that the (010) face developed more predominantly in the addition of B₂O₃ than of Li₂O. The two flux systems, i.e., in the addition of Li₂O and/or B₂O₃, have been found good for synthesis. Now, we started an attempt to grow a single crystal of anorthite by using a seed crystal but unfortunately did not succeed in growing large enough.

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Chromian epidote occurs rarely in nature. This study is the first report for synthesis and structural refinement for synthetic Cr-epidote. Experiments were conducted at 0.35-0.4GPa and 500°C for oxide mixture, and 0.8-1.5GPa and 500-800°C for gel starting material. Cr-epidote was successfully synthesized as predominant phase from the gel staring materials. The crystal structures were refined by X-ray Rietveld method. The cell parameters increase with increasing Cr content. Cr³⁺ shows stronger preference for M3 than M1, but M1 preference of Cr³⁺ is stronger than that of Fe³⁺ and Mn³⁺. The experimental result implies that Cr in the amorphous gels played an essential role for the crystallization of Cr-epidote. The source material of the transition elements is an essential factor for the genesis of epidotes.

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It has been well-known that calcite accelerates growth of ettringite crystals. In-situ observation of growing ettringite crystals was carried out to clear this origin. Only needle-like ettringite crystals were observed without addition of calcite, whereas both needle-like crystals and spherulites were observed in the presence of calcite powder. Spherulite, consisting of many acicular ettringite crystals and including calcite in its core, is formed first followed by generation of needle-like crystals. It may be considered that the cause of the acceleration of ettringite crystal growth due to calcite results from the rapid generation of spherulites and the growth of needle-like crystals with the high density by the secondary nucleation.

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We determined the step velocities of calcite in dissolution under Asp additive condition to elucidate the mechanism of morphological change of etch-pit caused by Asp. The step velocities were calculated from the data of in-situ AFM observation and ex-situ CLSM observation. The step velocities of obtuse steps were inhibited by Asp at more than 0.01 M. The effect of Asp to acute steps was also observed, but it was far less than to the obtuse steps. Moreover we observed the appearance of [010] step at 0.03 M and more than 0.03 M. These effects of Asp caused the drastic change of etch-pit shape.

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The protonic diffusion in portlandite was investigated by diffusion deuterium into single crystals of portlandite with a cold pressure vessel at 523-723K and 1.5Kbar. H-D diffusion profiles in the single crystal of portlandite were measured using micro Raman spectroscopy. The results of the analysis in the [100] direction show that frequency factor (D₀) is 3.7*10^-11m²/s and the activation energy (E) is 58kJ/mol (=0.61eV). A potential curve of the proton assuming Morse function was calculated from the frequencies of overtone modes of OH stretching vibration. The potential barrier between the oxygen atoms derived from the potential curve suggests that a proton can transfer to neighbor hydrogen vacancy site when O-O distance is shortened to 3.01angstrom (0.61eV) from 3.31 angstrom (0.98eV) by thermal vibration of the oxygen atoms.

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(Ce_x,Gd_1-x)_9.33(SiO₄)₆O₂ single crystals were grown by the µ-PD method. From the structural analysis, the lattice constants increased with increasing Ce concentration. Two nonequivalent crystallographic sites were found for Gd (Ce), 6h and 4f sites. It was revealed that most of Ce locate at Gd(6h) site. XANES analysis revealed while almost all Ce exist as Ce³⁺ in the crystals, a trace amount of Ce exist as Ce⁴⁺. The X-ray excited luminescence spectra of the crystals showed a peak around 400 nm originating from the Ce³⁺ 5d-4f transition. The corresponding decay time is about 25 ns.

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There are many micro-nano sized minerals in meteorites, especially carbonaceous chondrites. This research, we performed the synthesis to make various forms of them. In the experiment, the starting materials were combined 15 kinds of reagent, referring Greenberg and Li(1998). And then, they have run at hydro-thermal condition after they were mixed diamond seed or Iron powder. Through the experiment, the starting material, temperature, pressure, and time were arbitrarily selected. Obtained sample were dried in the room temperature in the atmosphere. The samples were observed with scanning electron microscope (SEM) and transmission electron microscope (TEM).

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Experiments on the metasomatism were performed in a ferberite - aqueous CaCl₂ solution system at 130, 150 and 170°C. The replacement texture from ferberite to scheelite was confirmed in all experimental systems. On the basis of the observations of the resultant products by SEM, it was found that the crystal face of the sample became clear and transformed to an octahedron crystal with an increase in the reaction time and temperature. The size of the sample increased with time such that the replacement texture grew not only toward the inside of the sample but also on the surface of the starting material. This replacement texture from ferberite to scheelite is classified as the rim replacement texture by previous works.

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Dissolution behavior of muscovite under alkaline conditions at 25-50 °C was investigated using in situ atomic force microscopy (AFM) with an air/fluid heater system to derive reliable dissolution rates and determine the dissolution mechanism and the effect of temperature on the dissolution rates. The muscovite dissolution took place only at the edge surfaces that are lesser than a few percent of the total surface area (TSA), while the basal surfaces were completely unreactive. The edge surface area (ESA)-normalized dissolution rate at a certain pH and temperature condition, therefore, has a constant value independent of the size of etch pit or island (particle). The ESA-normalized dissolution rates derived from this AFM study were consistent with the dissolution rates renormalized to the estimated ESA of the earlier studies. In contrast, the TSA-normalized dissolution rates varied with the size of etch pit or island. The activation energy for muscovite dissolution under alkaline conditions was very close to that for montmorillonite and illite dissolution. A model dissolution rate equation, which simultaneously includes the effect of pH and temperature, was deduced from the effect of pH on the activation energy, the rate equation of muscovite dissolution at 25C, and the Arrhenius equation.

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